No abstract

Transplantation of cellular components of the permissive peripheral nerve environment in some types of spinal cord injury holds great promise to support regrowth of axons through the site of injury. In the present study, Schwann cell grafts were positioned between transected stumps of adult rat thoracic spinal cord to test their efficacy to serve as bridges for axonal regeneration. Schwann cells were purified in culture from adult rat sciatic nerve, suspended in Matrigel: DMEM (30:70), and drawn into polymeric guidance channels 8 mm long at a density of 120 x 10(6) cells ml-1. Adult Fischer rat spinal cords were transected at the T8 cord level and the next caudal segment was removed. Each cut stump was inserted 1 mm into the channel. One month later, a bridge between the severed stumps had been formed, as determined by the gross and histological appearance and the ingrowth of propriospinal axons from both stumps. Propriospinal neurons (mean, 1064 +/- 145 SEM) situated as far away as levels C3 and S4 were labelled by retrograde tracing with Fast Blue injected into the bridge. Near the bridge midpoint there was a mean of 1990 +/- 594 myelinated axons and eight times as many nonmyelinated, ensheathed axons. Essentially no myelinated or unmyelinated axons were observed in control Matrigel-only grafts. Brainstem neurons were not retrogradely labelled from the graft, consistent with growth of immunoreactive serotonergic and noradrenergic axons only a short distance into the rostral end of the graft, not far enough to reach the tracer placed at the graft midpoint. Anterograde tracing with PHA-L introduced rostral to the graft demonstrated that axons extended the length of the graft but essentially did not leave the graft. This study demonstrates that Schwann cell grafts serve as bridges that support (1) regrowth of both ascending and descending axons across a gap in the adult rat spinal cord and (2) limited regrowth of serotonergic and noradrenergic fibers from the rostral stump. Regrowth of monoaminergic fibres into grafts was not seen in an earlier study of similar grafts placed inside distally capped rather than open-ended channels. Additional intervention will be required to foster growth of the regenerated axons from the graft into the distal cord tissue.

ITO thin films were deposited on glass substrates by d.c. magnetron sputtering with varied oxygen flow rates. It was found that the optical absorption decreases and optical absorption edge has blue shifts with the increasing oxygen flow rate. Oxygen vacancy concentration was characterized and analyzed by XPS. It is shown that the oxygen vacancy concentration increases with oxygen flow rates, which is a different observation from the current understanding. The energy band structures associated with different vacancy concentrations of ITO were calculated using the first-principle based on density functional theory. The calculation results show that the increase of oxygen vacancies induces the increase of bands below Fermi level as well as the presence of a second band gap, which accounts for effects of the oxygen vacancies on the blue shifts.

No abstract

A highly electronegative carboxyl-decorated anionic metal−organic framework (MOF), (Me 2 NH 2 ) 2 [In 2 (THBA) 2 ]-(CH 3 CN) 9 (H 2 O) 21 (InOF; H 4 THBA = [1,1′:4′,1″-terphenyl]-2′,3,3″,5,5′,5″-hexacarboxylic acid), with high-density electronegative functional sites was designed and constructed. One unit cell of InOF possesses 12 negative sites that originate from the negatively charged secondary building unit [In(COO) 4 ] − and exposed carboxyl groups on the ligand. The abundant electronegative sites can facilitate the hopping of ions in channels and thus result in highly efficient ion conductivities for various metal ions. Our results show that Li + -loaded materials have a remarkably high ion conductivity of 1.49 × 10 −3 S/cm, an ion transference number of 0.78, and a relatively low activation energy of 0.19 eV. The Na + , K + , and Zn 2+ ion conductivities of InOF are 7.97 × 10 −4 , 7.69 × 10 −4 , and 1.22 × 10 −3 S/cm at 25 °C, respectively.

Due to serious global warming and environmental issues, the demand for clean and sustainable energy storage devices is significantly increased. Often accompanied by rapid growth of portable electronic vehicles and devices, massive electromagnetic wave pollution becomes unavoidable. To mitigate the above two issues, this mini-review summaries preparation methods and recent developments of MXene/polyaniline-based composites for their applications in electrochemical devices and electromagnetic interference shielding. Based on excellent synergistic effects between single compounds and designed hierarchical structures, MXene/polyaniline-based composites usually exhibit enhanced physical and chemical properties, showing great potentials in sustainable electrochemical properties and electromagnetic wave protections for human health as well as normal operation of precise electronic devices.

Inorganic oxides are recognized as attractive materials for developing anodes for wastewater treatment, potentially offering a cost effective solution for electro-oxidation. A key parameter in measuring the effectiveness of different anode materials is the oxygen over potential. In this paper, we study the role of Zn and Sb co-doping of SnO2 thin films to achieve enhanced oxidation potentials, suitable for use in wastewater treatment. The morphology, chemical, and electrochemical properties of the films were characterized, and as a result of an optimization study, suitable anode materials for wastewater treatment are identified.

Nickel and antimony co-doped Ti/SnO 2 (Ti/Ni-Sb-SnO 2 ) anodes were prepared by spray pyrolysis. Effects of nickel concentration on the structure and onset potential for oxygen evolution of Ti/Ni-Sb-SnO 2 anodes have been systematically investigated.XRD analyses suggest that SnO 2 thin films grow in preferential orientation along (101) plane as the nickel concentration increases. The enhanced onset potential of oxygen is above 2.4 V vs NHE due to the introduction of nickel doping, and increases slightly with the nickel concentration. The calculated results show that work function of Ni/Sb co-doped SnO 2 also increases with the Ni doping level, which contributes to the enhancement of onset potential for oxygen evolution.